(a) Field of the Invention
The present description relates to a thin film transistor (TFT) array panel for a liquid crystal display (LCD) or an organic light emitting display (OLED), and a manufacturing method for the same.
(b) Description of the Related Art
Liquid crystal displays (LCDs) are one of the most widely used flat panel displays. An LCD includes a liquid crystal (LC) layer interposed between two panels provided with field-generating electrodes. The LCD displays images by applying voltages to the field-generating electrodes to generate an electric field in the LC layer that determines orientations of LC molecules therein to adjust the polarization of incident light.
An LCD including two panels provided with field-generating electrodes respectively, wherein one panel has a plurality of pixel electrodes in a matrix and the other has a common electrode covering the entire surface of the panel, dominates the LCD market.
The LCD displays images by applying a different voltage to each pixel electrode. For this purpose, thin film transistors (TFTs) having three terminals to switch voltages applied to the pixel electrodes are connected to the pixel electrodes, and gate lines to transmit signals for controlling the thin film transistors and data lines to transmit voltages applied to the pixel electrodes, are formed on a thin film transistor array panel.
A TFT is a switching element for transmitting image signals from the data line to the pixel electrode in response to the scanning signals from the gate line.
The TFT is applied to an active matrix organic light emitting display as a switching element for controlling respective light emitting elements.
Meanwhile, chromium (Cr) is conventionally the dominating material for the gate lines and the data lines of a TFT array panel.
Considering the trend of LCDs of increasing size, a material having low resistivity is urgently required since the lengths of the gate and data lines increase along with the LCD size. Accordingly, there are limitations to applying Cr to a large size LCD.
Cu is a well-known substitute for Cr due to its low resistivity. However, the poor adhesiveness of Cu with a glass substrate and the difficulty in etching Cu are obstacles in applying Cu for use with gate and data lines.